Urology

Question 1

Embryology of the GU system

Answer 1

• Transient excretion at 4-5 weeks urine production from 10 weeks and then progresive production to term
• Week 4
  
  • Pronephros (paired blocks of intermediate mesenchyme, rapidly regresses in human)
  • Mesonephric mass (transient excretory role, will become definitive gonad, lateral to the mass forms the mesonephric ducts)
• Week 5
  
  • Mesonephric ducts (migrate caudally, duse with hind gut to form cloaca, distally ureteric buds develop)
  • Ureteric buds (grow cranially towards and into the metanephric mass)
• Week 6-10
  
  • Fusion of ureteric bud and metanephric blastema initiates nephrogenesis
  • Ureteric bud gives rise to everything from collecting duct down and metanephros to everything from collecting duct up
  • At the end of week 7 the ureter inserts into the bladder
  • At the end of week 8 te kidneys find themselves at the upper lumbar level
• Weeks 15-36
  
  • Ureteric bud derivatives complete by 15 weeks
  • Nephrogenesis continues until 36 weeks

Question 2

Definition of obstruction

Answer 2

• An impedance to urine flow, which causes gradual and progressive renal damage
• Defined based on severity, duration and on location:
  
  • Pelvis/Ureter (PUJ)
  • Ureter
  • Ureter/Bladder (VUJ)
  • Bladder
  • Urethra

Question 3

Presentation of obstruction

Answer 3

• Antenatal
• Asymptomatic
• Pain
• Infection
• Haematuria
• Mass

Question 4

‘Classical’ PUJ

Answer 4

• Mass, infection, pain or incidental USS finding
• Operative decision depends on function
  
  • Pyeloplasty
  • Nephrectomy
• Hydronephrosis also affects operative decision (<15mm in diameter minimal follow-up >40mm pyeloplasty or nephrectomy)
• Generally good results but can have stent problems, infection and acute obstruction following surgery

Question 5

PUV

Answer 5

• Renal impairment with 70% presenting <1 year of age
• Palpable bladder, hydronephrosis, weak stream, UTI, sepsis, acidosis, respiratory distress, electrolyte changes
• Establish drainage (catheter), aggressive fluids and electrolytes, antibiotic cover, surgical drainage if evidence of inadequate drainage and nephrology management
• Serial USS to monitor
• Surgery can be used (endoscopic valvular ablation)
• 70% have preserved renal function throughout childhood - normal function at 2 years a good prognostic sign
• PUV accounts for 1% of all ESRF

Question 6

Vesicoureteric reflux

Answer 6

• Functional obstruction
• Identified by MCUG or MAG3 micturation
• Risk of infection and renal scarring
• Lower grades improve spontaneously
• Surgery may reduce pyelonephritis but no changre in scarring - STING offers low morbidity reasonable success
• Post STING infection is commonest complication

Question 7

Facts about foreskins

Answer 7

• Ballooning is normal
• <2% of boys circumcised
• Non-retractily foreskin not pathological
  
  • 95% not retractile at birth
  • 10% by 5 years
  • 5% by 10 years
• Balinitis is usually chemical

Question 8

Circumcision

Answer 8

• Advantages
  
  • Lower UTI risk?
  • Malignancy?
  • Sexual enhancement?
  • AIDS/STDs?
• Disadvantages
  
  • Painful
  • Complications
  • Cultural
  • No evidence

Question 9

Neonatal torsion

Answer 9

• Cause
  
  • Birth trauma
  • During labour
  • Bad luck?
• Fix contralateral? - controversial

Question 10

Hydroceles and hernias

Answer 10

• Hernia
  
  • Can’t get above/characteristic reduction
  • Unlikely to resolve
  • Risk of incarceration/strangulation and damage to testis
  • Should be treated soon
  • Operation = herniotomy
• Hydroceles
  
  • Fluid filled cyst with normal cord above
  • Commonly resolve
  • Low risk of problem
  • Allow to resolve offering surgery after 2-4 days
  • Operation= ligation of PPV

Question 11

Cryptorchidism

Answer 11

• Impalpable
  
  • Laparoscopy, staged orchidoplexy, guarded results
• Ectopic
  
  • Open single stage, usually good result
• Undescended
  
  • Open (or lap), mixed results depending on position

Question 13

Stones

Answer 13

• Presentation
  
  • Pain
  • Haematuria
  • Infection
  • Previous stones or urological surgery
• Causes
  
  • Infective
  • Metabolic
  • Medication
• Need medical workup
• Managemnent uses complex equiptment